The present invention relates to a ski boot which is put on and taken off by the foot entering and leaving through the rear, and of which the position of the top part of the upper with respect to the bottom part of the boot, particularly during the movements of rear support whilst practising skiing, is determined by cooperating means provided between different elements composing the top part of the upper and the bottom part of the boot.
To this end, these boots are generally designed so that they are composed of at least two elements pivoted on each other. The first of these elements which forms a rigid bottom part of the shell, is intended to cover and surround the front part of the foot and the first element extends for example from the zone of the top of the foot to the tibial zone of the bottom of the leg, as a flexible upper. This first element is in one piece, but its rigidity varies according to the zones. The second element, or rear cover, also called "spoiler", is pivoted on the first element so as to pivot from an open position to a closed position. This second element covers the heel at the rear of the boot and extends upwardly to surround the back of the bottom of the leg. Moreover, its rigidity is greater in the tibial zone covering the bottom of the leg. When it is in open position, this second upper element is separated from the first element so that the angle of opening is sufficiently large to allow the skier's foot to enter from the rear to the front.
During skiing, the said two elements are held in closed position by any suitable means, such as straps, bands with buckles and hooks or the like, so that the angle and the bottom of the leg are firmly surrounded by the spoiler-upper assembly.
Ski boots are already known in which the above-mentioned cooperating means are constituted by a buckle and a hook which maintain the bottom of the spoiler tight on the bottom of the shell, in the zone located just above the ankles. However, the tightening thus obtained may not be sufficient due to the forces required to close the hook-buckle assembly, due to the considerable rigidity of the spoiler. As this latter is virtually undeformable, there could be no increase in the frictions which prevent it from pivoting rearwardly upon the considerble forces due to the movements of rear support. These forces tend to deform the upper which undergoes a rearward extension, this increasing the rearward angular movement of the whole of the upper of which the spoiler is part. Consequently, the necessary rear supports are lacking for the skier.
Ski boots are also known, which are put on from the rear, in which the limitation of the rearward angular movement of the spoiler is ensured only by the connection made by the hook of the bottom of the leg between the spoiler and the upper. In this case too, the necssary rear supports may be lacking for the skier when skiing. In other known ski boots, the angular blocking of the upper of these boots is effected by adjustable means which may or may not be elastic. However, these devices are essentially intended for boots in which, to put them on, the upper pivots with respect to an axis located in the zone of the ankles having an opening on the front of the foot. These devices have the drawback of being complex and consequently expensive.
In particular U.S. Pat. No. 3,543,421 describes a ski boot constituted by a rigid lower part and an upper part pivoted on said lower part, a support member being mounted on said upper part, this support member being able to come into a first position in abutment on the lower part. In this type of construction, it is necessary to provide, on this lower part, supplementary support means ensuring the position in abutment of the upper part or "collar" of the upper which is totally pivoted on the lower part. Moreover, the supplementary support means increase the cost price of the boot not only due to the cost of the parts but also due to the costs of assembly on the bottom of the shell.